Automatic hot bed



April 964 F. R. ANDERSON AUTOMATIC HOT BED Filed Jan. 24, 1962 1 E III (II III lrivli INVENTOR. BY WW M 27 mm United States Patent 3,129,530 AUTOMATIQ HOT BED Frank R. Anderson, The Richard C0., Baldwin St. Extension, Meadville, Pa. Filed Jan. 24, 1962, Ser. No. 168,372 1 Claim. (C1. 47-19) This invention is an automatic hot bed utilizing the radiant heat of the sun and arranged so that the temperature can be controlled within limits insuring proper growth of the plants. The hot bed has solid north and south walls and glass east and west walls. A glass top is hinged to the south wall by an offset hinge so that as the thermostat lifts the top a ventilating opening is created between the top and the upper edges of all walls. The thermostat is located adjacent the south wall and is protected by a sunshade covering the top and the east and west sides.

In the drawing FIG. 1 is a side elevation of the hot bed and FIG. 2 is a plan view.

The hot bed is open at the bottom and has north and south walls 1 and '2 and east and west walls 3 and 4. The north wall 1 is higher than the south Wall and both the north and south walls are solid. Conveniently, these may be made of plywood. The north wall never receives the direct rays of the sun. The south wall intercepts the most intense radiation and protects the plants from scorching. The east and west walls 3 and 4 are of identical construction and comprise a horizontal frame member 5 at the bottom, upright frame members 6, 7 and an inclined frame member 8 at the top. A pane 9 of glass is suitably held in the window opening defined by the frame members 5-8. The ends of the top edges 10 and 11 of the east and west Walls are flush with the top edges 12 and 13 of the north and south walls. Closing the top of the hot bed is a frame having side rails 14, 14a, respectively resting on the top edges of the east and west walls and cross members 15, 15a, re spectively resting on the top edges of the north and south Walls. Suitably secured Within the frame is a pane of glass 16. The top frame of the hot bed is hinged to the east and west walls by hinge members 17, 18 having hinge pins 19, which are ofiset both to the south of and vertically above the upper edge 13 of the south Wall. Because the hinge axis is outside the south wall, as the top frame hinges upward about the hinge pins 19 and 20 there is an initial opening established between the top frame and the upper edges of the north, south, east, and west walls. This permits ventilation in any direction which assists in maintaining the desired controlled temperature within the hot bed. At opposite sides of the top frame are brackets 21, 22 carrying a counterbalance weight 23 which makes the top frame easy to hinge even though the hinge pins 19, 20 are located at one end of the frame. A safety chain 24 may be provided between the north wall and the front of the top frame to limit opening under gusts of wind.

The thermostatic control is provided by thermostatic bellows 25 carried by a bracket 26 attached to the inner side of the south wall 2. The thermostatic element 25 is accordingly protected from the most intense rays of the sun. Extending over the top and east and west sides of the thermostatic element and in spaced relation thereto is a shield 27 of U-shaped cross sections which may be suitably supported on the south wall 2 for exice ample by a tab 28. The U-shaped shield 27 extends over the top of the thermostatic element 25 and has depending walls 29 and 30 which intercept rays of the sun coming respectively from the West and east and prevent erroneous operation of the thermostat. The shield 27 is open toward the north wall, but that is immaterial because there is no need for a shield for the rays of the sun coming from that direction. The shield does not interfere with the free circulation of air about the thermostatic element necessary to maintain the required temperature.

The thermostatic element 25 ope-rates a rod 31 having its upper end 32 received in a recess 33 on the under side of a bracket 34 attached to the top frame member 15. The top frame is biased to the closed position by gravity. The thermostatically controlled rod 31 pushes up in accordance with the temperature within the hot bed. Control of the temperature at which the top frame opens is adjusted by varying the length of the rod 31, for example by a screw adjustment 35. The temperature at 'which the top starts to open can be adjusted for any desired value, for example from F. up.

In use, the hot bed is merely placed over the top of the plants to be protected. The protection is adequate even when there is snow on the ground. The protection of the thermostat from the direct rays of the sun assures response of the thermostat to the air temperature within the hot bed rather than to the radiant heat received from the sun. This maintains accurate temperature within the hot bed. The offset hinge which insures opening between the top frame and all upper edges of the walls provides the ventilation throughout which is necessary to maintain the hot bed temperature. Whenever the top frame swings upward under the influence of the thermostat, there is a ventilating opening between the upper edges of north, south, east and west walls.

What is claimed as new is:

A hot bed having front, back and side Walls, the side walls being glassed and having upper edges inclined upwardly from front to back with the ends substantially flush with the upper edges of the front and back walls, the back wall being higher than the front wall and both the back and front walls being solid, a glassed top frame closing against the upper edges of the front, back and side walls, means hinging the top frame about an axis offset to the front of the upper edge of the front wall, a thermostat bellows within the hot bed adjacent the front wall, brackets fixed to the top frame and projecting in front of the hinge means, a counter balance weight carried by the brackets in front of the hinge means, and a connection from the thermostat bellows to the top frame for positioning the top frame relative to the upper edges of the walls.

References Cited in the file of this patent UNITED STATES PATENTS 38,656 Crozier et al May 26, 1863 106,298 Wells Aug. 9, 1870 2,592,976 Thom-as Apr. 15, 1952 2,608,797 Rawson Sept. 2, 1952 FOREIGN PATENTS 804,500 Germany Apr. 23, 1951 384,395 Great Britain Dec. 8, 1952 

